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- ; RUN: opt < %s -instsimplify
- ; The mul can be proved to always overflow (turning a negative value
- ; into a positive one) and thus results in undefined behaviour. At
- ; the same time we were deducing from the nsw flag that that mul could
- ; be assumed to have a negative value (since if not it has an undefined
- ; value, which can be taken to be negative). We were reporting the mul
- ; as being both positive and negative, firing an assertion!
- define i1 @test1(i32 %a) {
- entry:
- %0 = or i32 %a, 1
- %1 = shl i32 %0, 31
- %2 = mul nsw i32 %1, 4
- %3 = and i32 %2, -4
- %4 = icmp ne i32 %3, 0
- ret i1 %4
- }
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